Image: UbisoftOfficial screenshot from Ubisoft.
Ninjerilla asks you to capture an FND base without being detected in solo play. It is a stealth challenge, and smaller bases are the easiest place to try.
1. Pick a small FND base. 2. Mark every soldier and camera with your phone. 3. Take guards out with silenced weapons and takedowns. 4. Finish the capture without anyone raising the alarm.
A suppressed rifle and stealth gear make it easy. If you get spotted, reload a checkpoint or leave and try another base. It goes well with Didn't See That Coming!.